The SureThing project will address a timely Internet of Things security need: creating and validating location certificates so that devices can make proof of their location or ask proofs to others. The location verification uses state-of-the-art techniques, including: locality-sensitive network measurements and ambience sensing; combined with diverse witness models which use anonymization techniques. The contributions of the project will be validated with a Smart Tourism use case, that will make use of fast proofs for a reward program; and with a Smart Taxes use case, which will use digital signatures and a Blockchain-based distributed ledger to produce long-term proofs, compliant with more demanding business requirements. The widespread use of SureThing location proofs will significantly improve the security decisions of policies for the Internet of Things, leading to more secure and trustable services in the near future.